This paper presents an application of ultrahigh-performance liquid-chromatography - quadrupole - orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) for the ultra-trace analysis of 12 β2-agonists in pork, beef, mutton and chicken meat. The mass spectrometer was operated in Full MS/dd-MS(2) (data-dependent MS(2)) mode, under which a Full MS scan was followed by a dd-MS(2) scan with a fragmentation energy. The quantification was achieved using matrix-matched standard calibration curves with salbutamol-d3 and clenbuterol-d9 as the internal standards. The method validation included assessment of selectivity, sensitivity, calibration curve, accuracy, precision, recovery, matrix effect and stability. The results show an exceptional linear relationship with the concentrations of the analytes over wide concentration ranges (e.g., 0.01-50 μg/kg for clenbuterol) as all the fitting coefficients of determination r(2) are >0.9986. The detection limits (LODs) were in the range of 0.0033-0.01 μg/kg, which was much lower than the current reported methods. The recoveries were able to reach 73.0-88.7%, while the matrix effects ranged from 83.7% to 92.8%. Analysis of 400 pork, beef, mutton and chicken samples reveal that only 4.25% samples were positive for β2-agonists. The detected β2-agonists involved salbutamol, clenbuterol, ractopamine and clorprenaline. Overall, the novel Q-Orbitrap technique was demonstrated to have great performance for the screening, identification and quantification of ultra-trace β2-agonists used in food animal muscles, which helps to ensure food safety and public health.
Keywords: Detection; Food animal muscles; Orbitrap; Residues; β(2)-Agonist.
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